Squat
Butt Wink in the Squat: What It Is and How to Fix It
June 5, 2026 · 5 min read
"Butt wink" is the small backward tuck of your pelvis at the very bottom of a squat. A little is normal; a lot under heavy load is worth fixing. Here's why it happens and what actually helps.
What butt wink is
At the bottom of the squat the pelvis rotates under (posterior pelvic tilt) and the lower back rounds slightly. You'll see the hips "tuck" right at the deepest point.
Does it matter?
A small amount at the very bottom is normal and not dangerous for most people at moderate loads.
It becomes a concern when it's large, repeated, and happening under heavy weight — that's load on a rounding spine.
Why it happens
Common causes: limited ankle or hip mobility, squatting deeper than your current mobility allows, a stance that doesn't fit your hips, or losing your brace at the bottom.
How to fix it
Squat to the deepest point where you can hold a neutral pelvis — don't chase rock-bottom if you can't keep position yet.
Widen your stance or turn your toes out, improve ankle mobility (or briefly elevate your heels), and brace hard before you descend.
Check it on video
Butt wink is hard to feel. Film from the side at hip height and watch your pelvis at the bottom.
FormLens measures your hip and spine angles on every rep, so you can see whether a fix is actually working.
Check your own form
Film a set and FormLens scores your form, measures depth and asymmetry, and shows you exactly what to fix.